Internal-combustion engine



April 7, 1925. 1,552,306

J. DAVIDSON INTERNAL COMBUSTION ENGINE Original Filed June 29, 1920 BM EBMMQMM attorney Patented Apr. 7, 1925.

UNETEQ STATES- JQHN DAVIDSON, DE BURTOhT-ON-TR-ENT, ENGLAND,

INTERNAL-GOIWZBUSTION ENGTNE.

Original application filed June 29, 1920,

Serial No. 392,754. Divided and this application filed. August 15,

1923. Serial NO- 657,522

To (ZZZ whom it may concern.

Be it known that T, JOHN DAvinson, a British subject, residing at Burtoiron-Trent, in the county of Stafford, England, have invented certain useful Improvements in Internal-Combustion Engines, ot which the following is a specification.

This invention relates to internal combustion engines and is a division of my application for patent, Serial Number 392,754 filed the 29th June, 1920, the object of this invention is to render the same generally more eiiicient in action, than hitherto has been the case.

T attain my object by the mechanism illustrated in the accompanying sheet of drawings, in which Figure 1 is a view in vertical section of an internal combustion engine having a double pumping action.

Figure 2 is a sectional plan view of an engine cylinder having an increased number of working pistons.

Similar numerals refer to similar parts throughout the several views.

Referring to the drawings, 1, 2 and 3, 4 are the working cylinders and in the former are formed the inlet ports 5, 6.

Similar ports 7 8 are formed in the cylinders 3, 4 to act as exhaust ports. The working pistons 9, 10 and 11, 12 are mounted on and fixed to the large diameter or charging pistons 13, 14 which reciprocate in the cylinders 15, 16 formed below the working cylinders.

The working pistons 9, 11, 10,12 are connected to the charging pistons 13, 14 by piston rods 38 which are screwed into the working pistons and pass through a partition 39 which separates the pump cylinders 13 and 14 from the undersides of the working pistons 9, 11, 10, 12. The undersides of the working pistons 9, 11, 10, 12 are employed as air scavenger pumps and the pump cylinders 13, 14 to pump the combustible mixture or the like; or the undersides of the working pistons 9, 11, 10, 12 are employed as a gas or the like pump and the pump cylinders 13, 14 to the pump air only. Suitable ports 40 and 41 are provided in the working and charging cylinders, for the delivery of the scavenging air and the combustible mixture or the like from the pump chambers on either side of the partitions 39,.

As illustrated in the drawings the engine is preferably provided with at least two sets of cylinders, the cranks being so angularly displaced in reiation to one another that the pump of one line serves to charge the working cylinders of the next line. A piston valve 17 actuated from an eccentric on the engine crank shaft governs the delivery of the combustible mixture, scavenging air, or the like and is preferably arranged as shown to reciprocate at an angle to the line of reciprocation of the working cylinders.

In large powered engines in order to dispense with the necessity for cooling the working pistons with Water or oil, three or more working pistons may be employed in connection with each charging piston, in lieu of the two illustrated in Figure 1, it then being possible to keep the diameter of the working pistons within limits which will prevent excessive heating. In Figure 2 four working cylinders 42 are shown by way of example, containing four working pistons 43 all of which are connected to one pump piston 44. All the working piston chambers are in open communication with one another at both ends of the working cylinder casting 45, and the inlet to the working cylinders is at 46 while the exhaust passes through the outlet 47 The hereinbefore described and hereinafter claimed improvements are applicable to all engines having a plurality of working pistons connected to a charging piston including those constructed to operate on the Diesel and semi-Diesel principles.

Jackets 48 may be provided round the pump cylinders 15 and 16 when they are employed for charging with the combustible mixture, to receive hot exhaust gases from the engine, but when employing the lower side of the working cylinders 1, 3, 2, 4 for this purpose, the acket 48 would be provided around the lower part of said working cylinders to .receive hot exhaust gases and thereby warm the combustible mixture.

The use of a jacket or jackets as hereinbefore described is particularly useful when paraflin is employed for fuel, or the engine is running on light loads, and consuming paraflin or any other fuel.

I claim 1. In an internal combus ion engine, a

plurality o1"- cylinders in open communication at one end, a common combustion herd provided at the other end, a single worln g piston in each cylinder dividing each cylinder into a Working chamber and a pump chamber, a larger cylinder at the first namec end of the said cylinders separated from the first named cylinders, a piston in the larger cylinder, and a connecting rod pivotally connected to the last named piston which serves both as a pump piston and as a cross-head.

2, In an internal combustion engine, a plurality of Working pistons; a pump piston; piston rods connecting all the Work ing pistons to the pump piston; Working cylinders each of Which contains one of the Working pistons; a stationary common combustion head at one end of the Working cylinders; a pump cylinder at the other end of the Working cylinders; a partition between the Working cylinders and the pump cylinder; holes in the partition in Which the piston rods reciprocate; a gudgeon pin connection on the pump piston; ports in the end of Working cylinders near the partition; ports in the pump cylinder near the partition; and a piston valve controlling the said ports.

3. in an internal combustion engine, pump cylinder; more than two Workin cylinders of sma ler diameter arranged at one end of the'p 'np cylinder parallel with one another and Li open communication With one another at one end; a combustion head at the other end of the Working cylinders common to all oi the Working cylinders; a pump piston in he pump cylinder; more than two Working pistons in the Working cylinders each Working cylinder having one Working piston only; means enclosed in the pump and Working cylinders positively connecting the pump and Working pistons together; a connecting rod; and pivotal means on the outer face or the pump piston for direct connection or the pump piston to the connecting rod.

Signed at Manchester, in the county of Lancaster, England, this 31st day of July JOHN DAVIDSON. Witnesses ANNIE MGJANNETT, EDITH LILIAN VVooDWARD. 

